Cementitious wall board



)ma @if Cross Reference W. DUNSTAN. CEMENTITIOUS WALL BOARD. FILED SEPT Il i922 106. COMPOSITIONS, COATING 0R PLASTIC Feb 13, 1923 Patented Feb.-13, 1923. UNITED STATES PATENT OFFICE.

WILLIAM DUNSTAN, F VICTORIA, AUSTRALIA.

' CEMENTITIOUS WALL BOARD.

Application led September 11, 1922. Serial No. 587,541.

ToaZZ 10.710771tmoyconcern.' litchl or resin may be added to theface.

Be it known that ll'iLLrAu DUNSTAN, a. ccording to the degree of hardness resubject of the King of Great Britain, residquired for the composition from 1% to 1070 ing at 7 Eveline Street, Brunswick, in the of ferrie oxide or other metal oxide is in- Statc of Victoria, Commonwealth of Austraclu ed u some classes of clavs or slimcs lia, has invented new and useful Improvepossess sutlicient iron and alsolime. content. ments in Cementitious liall Board, of which The sheets for outside use may have a skin the following is a specification. deep face of cement applied thereto and for The object of this invention is the produodouble faced sheets, one exposed to the tion of a cenientitious composition capable weather and the other forming an interior of being moulded to form various articles or surface. the outer side is coated with a thin sheets o1' slabs which while possessing srin of cement and the interior side. with a strength and durabilitvv will be inexpensive similar laver of plaster of Paris 0r like cemf to produce as the constituent materials are natural or unmanufactured products. The invention also includes mechanical means for mixing the composition, feeding and polishing same in sheet form and drying .same i'ead57 for use.

A\nother advantage of this invention is that the sheets for instance used for interior or exterior purposes on a buildingI mabe readily manufactured on the site and to the exact size required. thus avoiding subsequent cutting. this advantage being possible owing to the simplicitv1 of the apparatus necessar` for manufacturing.T the articles.

A considerable range of material may be used as a basis for the composition, all of entitious material.

The sheets or moulded articles are expeditiously dried by artificial heat and do not require to be kiln-dried. y

The accompanying drawings illustrate diagramniatically a simple apparatus for use in manufacturing sheets or slabs of the composite material.

Fig. 1 being a general diagram and Fig. 2 a vertical section through a drying table;

F igs. 3 and 4 details ot' rollers shown in Fie. l, and

`ig. 5 a vertical section illustrating another form of smoothing roller.

The materials forming the body of the which materials are coiiiparativelv inexpencomposition and ,including fibre or hemp sive. For instance. the material may consist of Vclav. maia` lav. QPL-guas; and earth. s imcs from mines a r r i* w ere lig tness is c esireo. c a io and an;v of such materials mtlreac y water soaked. mapY be mixed together with water. into a stiff plastic condition. In order are fed into a trough or the like l. with petrifving agent and thoroughly puddled toto reinforce the mixture or material. fibre. tween the spikes of the other roller and 40 hem n. or like material is added and for asroller 8 is geared to revolve more rapidlyvv sisting in the binding and quick drying of the material. petrif'ving agents such as silicate of sod. oi calcium chloride previouslyv dissolved maxv lm Suid glue and cement.

ie sodium silicate iii proportion to the than roller 2 which has the effect of mixing thoroughly the composition and particularly the fibre while both rollers act to feed forward the composition.

B v means of :inv suit-able elevator 14. consisting for instance of idle rollers 15. thc material is delivered between one or more sets of rollers 5. rotated in opposite directions and at the same speed. the roller 6 being of much greater diameter than roller 5. These rollers determine the thickness of the sheets and besides feeding the composition forward the greater circumference of roller 6 operates to polish one surface of the composition. v

For the same purpose the upper rollers 6a (Fig-Mjmay be providedivith a series of radially projecting spring steel curved vvipers l1, which in contacting vvith'the composition trovvels same and produces a smooth surface. The diametric length betvveen the ends of opposite Wipers is greater than the diameter ot roller 5 yor alternatively the roller 6 is rotated more rapidly than roller 5. Furthermore. roller 6 or t3a is set obliquely Vto roller 5 in order to obviate transverse ridges being formed across the composition.

If the rollers 2, 3, are in vertical alignment or raised above the roller 5 the elevator is unnecessary in which case the material simply passes over idle rollers similar to rollers l5.

rl`he composition passes over idle rollers T and then along a metal plate S laid on a bench 9 and when the plate receives the desired length of composition for a sheet said length is cut ofi" and the plate is removed and replaced by another. The plate with the plastic sheet is then placed on a table l0 which is h rated. For the latter purpose the table top may be hollow and steam heated or jacketed or placed over an oren or the table top may be electrically heated. The sheet by either of these means is rapidly dried and is ready for use or it may then receive surface coats of cement or plaster or Paris if desired.

Many articles. especially for building purposes. may be manufactured by means ot moulds from this composition such tiles. slabs for vvall building, bricks and mouldings such as cornices. troughs and pipes and if desired such moulded articles may have met-al or other reinforcementsl which are placed in the moulds with the composition I claim l. A cementitious sheet. slab. and the lilac. comprising a mixture or earthy material. slimes from mines or creeks. Water. a long vegetable ibre as reinforcement. a petritying agent and a heavy metal oxide hardener.

2. An improved cementitious sheet. slab and the like, comprisingr a mixture of earthy material. -vvater,tibre, silicate ot soda and an iron oxide from one to teu percent.

3. An improved cementitious sheet or slab having a body7 comprising a mixture ot earthy material, vvater. fibre and a petrifying agent. and an outsitlesuriace ot' h vdraulic cement.

4. An improved cementitious slab or sheet having a body comprising a mixture ot earthy material, vvater, libre and a petritying agent, an outside surface of hydrauli'.l cement and an inside iinish coat of plaster of Paris.

5. An improved cementvitiousl sheet or slab, comprising a body composed ol a mixture of clay. slimes, hemp fibre and silicati` of soda, and a water-proof coating.

6. An improved cementitious sheet or slab, comprising a body composed oi" a mixture of clay.y slimes, hemp i'ibre and silicate of soda, a Waterproof coating and an outer surfaceof hydraulic cement.

7. An improved cementitious sheet or slab. comprising a body composed oi" a clay. chalk, slimes. long vegetable fibre. silicate o ll soda,A calcium chloride and iron oxide. having an outer cement coating.

8. An improved cementit-ious sheet or slab having a body comprising a clay. chalk. slimes, long vegetable libre, silicate ot' soda. calcium chloride and iron oxide. having an outer cement coating and an inner finishing coat ot' plaster of Paris.

9. An improved cement-itious sheet or slab having a body comprising a clay, chalk. slimes. long vegetal le libre. silicate of soda. calcium chloride and iron oxide. having a waterproof coating and an outer coatingr oi cement.

10. A11 improved cementitious` sheet or slab having a body comprising a clay. chalk. slimes, long vegeta-blc fibre, silicate or soda. calcium .chloride and iron oxide. having a Waterproof coating an outer coating ot cement and an inner -nishinfr coaty oiPv plaster .of Paris.

Dated this 9th day of August, 1.022.

VILLLXM DNSTAX. 

